Lifting device



June 9, 1953 K. HECKER 2,641,514

LIFTING DEVICE Filed Sept. 14, 1949 2 Sheets-Sheet 2 INVENTOR Harvard K. Hacker ATTO NEY Patented June 9, 1953 LIFTING DEVICE Harvard Kaufmann Hecker, Clayton, Mo., as-

signor to Curtis Manufacturing Company, a corporation of Missouri Application September 14, 1949, Serial No. 115,715

4 Claims. (01. 308 -4) This invention relates to improvements in lifting devices. More particularly, this invention relates to improvements in lifting devices that can be used in lifting automotive vehicles.

It is therefore an object of the present invention to provide an improved lifting device that: can be used to lift automotive vehicles.

In the construction of lifting devices which are operated by hydraulic or pneumatic pressure, it is customary to provide a plunger that moves relative to a cylinder to elevate or lower loads. This plunger must be guided in its movement relative to the cylinder; such guiding being particularly important where an eccentric load can be applied to the plunger.

Various constructions have been proposed and made to provide full and complete guiding of the plunger; and the most practical of those constructions fall into two general categories. One category includes those constructions which have guide shoes at the bases of the plungers, and wherein the guide shoes bear against precisely ground cylinder walls. The engagement between the guide shoes and. cylinder Walls will cooperate with the engagement between the sides of the plungers and guide bearings at the tops of the cylinders to provide accurate and positive guiding of the plungers as they telescope into and out of the cylinders. The other category includes those constructions which have removable guide bearing cages that closely surround and confine the plungers. The guide bearing cages have axiallyspaced bearing surfaces that are precisely machined, and those bearing surfaces provide the required guidance and support for the plungers.

In each of these various constructions it is necessary to provide precise boring of the cylinder walls or to provide precise boring of the guide bearing cages, and the cost of the boring operations is high. For these various reasons prior cylinder and plunger constructions for lifting devices are objectionable. The present invention obviates these objections by providing a cylinder and plunger construction for lifting devices wherein the cylinder need not be precisely bored or ground. cheaper to manufacture than are prior cylinder and plunger constructions. It is therefore an object of the present invention to provide a lifting device that can be made without requiring the principles and teachings of the present in- Such a construction is easier and precise boring or grinding of the cylinder and that permit the plunger to shift its axis relative to the axis of the cylinder, and thus will enable the guide shoe on the plunger to move radially as it follows the high places and low places on the cylinder wall. With such a construction it is only necessary to smooth the rough places of the cylinder walls; and this can be done quicker and at less cost than is required in precision boring or grinding of the cylinder walls. It is therefore an object of the present invention to provide a lifting device with a tiltable guide bearing at the top of the cylinder.

The guide bearing provided by the present invention is a metal sleeve with an undercut portion on the exterior thereof. That undercut portion permits the guide bearing to tilt relative to the cylinder. The portion of the sleeve which is not undercut will thus act as a pivot to facilitate tilting of the guide bearing relative to the cylinder.

Where the cylinder is made in accordance with der. It is therefore an object of the present invention to provide a cylinder that can be made from polished seamless tubing. I

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description a preferred embodiment of the present invention .is shown and describedbut it is to be understood that the drawing and accompanying description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

In the drawing Fig. l is a cross-sectional broken view of a cylinder and plunger that are made in accordance with the principles and teachings of the present invention,

Fig. 2 is a perspective view of the guide bearing used in the cylinder of Fig. 1, and

Fig. 3 is a larger cross-sectional view of the guide bearing and a portion of the cylinder shown in Fig. 1.

Referring to the drawing in detail, the numeral l6 denotes a sleeve that is preferably made from a section of seamless tubing. This sleeve has a transversely disposed closure l2 at the lower end thereof; and that closure has a stop l4 projecting upwardly therefrom. The closure I2 is preferably secured to sleeve by welding. A second sleeve, of larger diameter than .sleeve It, is denoted by the numeral I6; and the sleeve I6 is secured to the sleeve [0, by welding or other suitable means. The sleeve I6 telescopes over and snugly engages the upper end of sleeve .16; and the two sleeves form a strong, liquid-tight cylinder. The sleeve l6 also is preferablyma'de of seamless tubing. A flange 18' of annular form is provided at the top of the sleeve [6; and that flange may be secured to the second sleeve 16 as by welding or other suitable means. A boss 23 is provided at one side of the sleeve l6, and that boss is provided with an opening 22. The boss 2|] can be-connected to a source of hydraulic fluid and the opening 22 will permit that fluid to enter the cylinder formed by sleeves HI and i6. A groove 24, of annular configuration, is formed in the inner wall of the sleeve i 3; and-that groove is spaced only a short distance below the upper end of the cylinder formed from sleeve 1'0 and sleeve 16.

The seamless tubing, used in making the sleeve l0 and the sleeve I6, will have the approximate diameters required, but their inner surfaces may have some burrs orrough places. These burrs or rough places can be removed by mounting a grinding wheel on a flexible rotating shaft, tele- I scoping the sleeves over the grinding wheel, and moving the sleeves axially and circumferentially while holding them in contact with the grinding wheel. This grinding wheel may'not grind away all of the high spots or low spots on the inner surfaces of the sleeves 10 and 16 but the inner surfaces of sleeves I0 and I6 will be approximately true. By following this manner of assembling and grinding the sleeves [-0 and I6, it is possible to obtain an inexpensive, sturdy, ground cylinder with a shoulder spaced below the upper end thereof.

A plunger 26, preferably made from a section of seamless tubing, is provided; and that plunger is dimensioned to telescope within the sleeves l0 and I6. Plunger 26 has a closure 26 spaced upwardly from the bottom thereof, and that closureextends from wall to wall of the plunger 26. The closure is preferably secured to the plunger by welding. The upper end of the-plunger 26 will support a superstructure, not shown, which can be used to engage and support the chassis of a vehicle. That superstructure can support all portions of the vehicle, or it can be dimensioned to support just the front end or the rear end of the vehicle. The plunger 26 has a reduced diameter section 30 at the bottom thereof; and that reduced diameter section receives "aguide shoe 32. The guide shoe 32 is preferably made of cast iron and it has a smoothly ground outer surface. The guide shoe 32 is dimensioned so it fits within the sleeve l0 and will pass through that section of sleeve 10 which has the smallest mean cross section. In selecting the guide shoe for a particular plungen a number of guide shoes 32 of slightly differing diameters are provided,

and those shoes are successively inserted into sleeve [0 until one is found .that passes all the way through that sleeve; An opening 33 is provided in the wall of the plunger 26 below the closure 28 and above the guide shoe 32. That .opening will permit air, .oil or other fluid to enter the space defined by the closure l2, the walls of sleeve l0, closure 28, and the walls of piston 26.

The guide shoe 32 is held in position relative to the plunger 26 by machine screws 34. The shoulder between the normal diameter section of plunger 26 and the reduced diameter section 30 of plunger 26 will ofier additional support to the guide shoe 32 whenever the plunger '26 moves downwardly in the cylinder. A stop ring 36 is secured to the exterior of the plunger 26, as by welding; and that stop ring is spaced intermediate the top and bottom of the plunger 26.

. A guide bearing-38 is disposed within the sleeve fl fi and the lower end of that guide bearing will rest upon and "be supported by the top of the sleeve 10. As a result, the shoulder formed by sleeves l0 and i6 will confine that guide bearing. 'The guide bearing 38 has a portion of normal diameter which loosely fits within the sleeve [6 of the cylinder; and 'it has a reduced diameter portion 40. Theloose diameter portion 40 of'guide bearing 38, and the loose fit of the guide bearing 38 in sleeve l6, enable that guide bearing-to tilt relative to the axis of the cylinder formed by sleeves l0 and I6. If desired, the portion of reduced diameter of guide bearing 33 could *be made by tapering the lower end of that bearing.

A pressure-distributing ring 42 bears against the top of the guide bearing '38; and the :pressure-distributing ring '42 is held in position by a retaining ring 44. This retaining ring, which is a snap ring, fits within the annular groove 24in the sleeve 16; and it positively-holds the pressuredistributing ring 42 against undersired removal from the sleeve i6. Howevenwhenever it is 'desirable ItO remove the guide bearing 38 or the plunger 26 from the cylinder, it is only necessary to bend the retaining ring '44 and move itoutof the groove 24; and then lift that ring and the pressure-distributing ring 42 out of the cylinder. Thereafter the guide bearing 38 and the plunger 26 can be telescoped out of the cylinder formed from sleeve 10 and sleeve 16.

A packing-supporting ring '46 rests upon the retaining ring 44, and that ring supports two sections of chevron packing 4B. The chevron packing v48 :bears against the sleeve 136 and against the plunger 26, and doing so it forms a liquid- -tight seal between that sleeve and that plunger. A packing gland 50 overlies the chevron packing 48 'andalso .overlies the flange ;I 6-on thesleeve :16.

A sealing and wiping ring 152, prefer-ably of neoprene or other resilient, oil-resistant mate.- rial, encircles the upper end of the plunger :26. This ring will wipe off of the plunger :26 any hydraulic fluid that may pass upwardly through the packing 48 and it will also wipe ofi dust and other foreign particles that might engage and adhere to the plunger 26. An extensible spring -54 encircles the sealing and wiping ring 52, and it holds that ring snugly against the piston :26. A cover-56 surrounds and encloses the sealing and wiping ring :52 and the extensible ring 54, and that cover is secured to the gland 350 by screws 58. These same screws secure the gland 5.0 to the flange 18 of. the cylinder. The wiping ring 52 protects the plunger and the walls of the cylinder against scoring, as by wiping dust and gravel off of the plunger.

The lifting deyice provided by the present in.- vention is extremely desirable because the piston and cylinder can be made easily and inexpensively. The present invention obviates the need of boring or grinding the interior of th Cylinder tomake it precisely concentric; instead, it makes it possible to select seamless tubing of the desired diameter, grind off the burrs and rough places, and then assemble the tubing to form the cylinder. The plunger and cylinder will operate effectively, and the cylinder will support and guide the plunger even though there are high spots and low spots on the inner surface of the cylinder. The guide shoe, which will have been selected by a trial and error method, will pass over the high spots and low spots of the cylinder; and the tilting of the plunger due to high spots will be accommodated by tilting of the guide bearing 38.

In assembling the lifting device, the sleeve ID has the closure I2 secured thereto, and the sleeve 16 has the flange l8 and the boss 20 secured thereto. Then the two sleeves l0 and I6 are secured together to form the cylinder, preferably by welding. The closure 28 is secured to plunger 26, the stop ring 36 is secured to plunger 26, the opening 33 is drilled, and then the guide shoe 32, which is selected by attempting to pass guide shoes of progressively smaller size through the cylinder, will be secured to the plunger. Thereafter the plunger is telescoped into the cylinder, the guide bearing is telescoped over the plunger and caused to rest against the top of sleeve [0, and pressure-distributing and snap rings are placed within the cylinder, the packing-supporting ring and the packing are inserted, and then the gland and the wiping ring and its spring and cover are secured to the flange [8.

A clearance of several thousandths of an inch is provided between the exterior of the guide bearing 38 and the interior of the sleeve I6. That clearance coacts with the reduced diameter portion of guide bearing 38 to permit limited tilting of the guide bearing and plunger.

In the operation of the lifting device, hydraulic fluid will be introduced into the cylinder through opening 22 in boss 20. That fluid will pass down along the sides of plunger 26, will pass through the opening 33, and will then act upon closure 28 to urge plunger 26 upwardly. The guide shoe 32 will bear against the inner surface of the cylinder and will guide the plunger 26 in its upward movement. The stop ring 36 will limit upward movement of the plunger, as by engaging the bottom of the guide bearing 38. That stop ring will also facilitate removal of guide bearing 38 from the cylinder, as by enabling lifting of the plunger to lift the guide bearing. Release of the pressure on the hydraulic fluid will permit the plunger to move downwardly in the cylinder.

Whereas a preferred embodiment of the present invention has been shown and described in the drawing and accompanying description, it should be obvious to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

What I claim is:

1. A lifting device that comprises a cylinder which has a ground inner surface with high spots and low spots, said cylinder including an elongated tube with a closed bottom and an open top and a short tube of larger diameter fixedly secured in telescoping relation to said elongated tube at the upper end of said elongated tube, the top of said elongated tube constituting an inwardly projecting shoulder intermediate the top and bottom of said cylinder, a guide bearing, said guide bearing being a sleeve which has an outer diameter smaller than the inner diameter of said short tube but larger than the inner diameter of said elongated tube, one portion of the exterior of said guide bearing fitting loosely withinqsaid short tube and another portion of the exterior of said guide bearing being cut away to have a diameter smaller than the diameter of the first said portion of the exterior of said guide bearing, whereby said guide bearing can tilt within said short tube, said guide bearing having the lower end thereof resting upon the top of said elongated tube and having the upper end thereof disposed below the upper end of said short tube, an annular retainer for said guide bearing that is disposed within said short tube and is securable to said cylinder adjacent the upper end of said guide bearing and that overlies part of the upper end of said guide bearing and thus limits appreciable longitudinal movement of said guide bearing while permitting limited tilting of said guide bearing relative to said short tube, an annular pressure-distributing ring disposed Within said short tube between the bottom of said retainer and the upper end of said guide bearing, a piston slidably disposed within said guide bearing and said cylinder for reciprocating move.- ment, a guide shoe adjacent the bottom of said piston, said guide shoe being dimensioned to move through said elongated tube and to follow said high spots and low spots in guiding said piston, and packing positioned adjacent the top of said retainer, said guide bearing being tiltable to permit said guide shoe to follow said high spots and low spots, the positioning of said packing adjacent said top of said retainer limiting leakage past said packing.

2. A lifting device that comprises a cylinder which has a surface with high spots and low. spots, said cylinder having an inwardly projecting shoulder intermediate the top and bottom of said cylinder, a guide bearing, said guide bearing being a sleeve which is disposed within said cylinder above said shoulder and which has one portion of the exterior thereof fitting loosely within said cylinder and having another portion of the exterior thereof cut away to a diameter less than the diameter of the first said portion of the exterior thereof whereby said guide bearing can tilt within said cylinder, said guide bearing having the lower end thereof resting upon said shoulder and having the upper end thereof disposed below the upper end of said cylinder, an annular retainer for said guide bearing that is disposed within and is securable to said cylinder adjacent the upper end of said guide bearing and that overlies part of the upper end of said guide bearing and thus limits appreciable longitudinal movement of said guide bearing while permitting limited tilting of said guide bearing relative to said short tube, a piston slidably disposed within said guide bearing and said cylinder for reciprocating movement, a guide shoe adjacent the bottom of said piston, said guide shoe being dimensioned to move through said elongated tube and to follow said high spots and low spots in guiding said piston, and packing positioned within said cylinder adjacent said retainer, said guide bearing being tiltable to permit said guide shoe to follow said high spots and low spots, the positioning of said packing adjacent said retainer limiting leakage past said packing.

3. A lifting device that comprises a cylinder which has a ground inner surface with high spots and low spots, said cylinder including an elongated tube with an inwardly projecting shoulder intermediate the top and bottom of said cylinder, a guide bearing, said guide bearing being 7 a sleeve which is disposed within said cylinder above said shoulder .and which has one portion of the exterior thereof fitting loosely within said cylinder and having another portion of the exterior thereof cut away to .a diameter less than the diameter of the first said portion of the 16X- terior thereof whereby :saidiguide bearing can tilt within said cylinder, said guide bearing having the lower end thereof resting upon saidshoulder and having the upper end thereof disposed below the upper end of -said cylinder, an annular :snap ring retainer for said guide bearing that isdisposed within a groove in said cylinder adjacent the upper end of .said guide bear-ing and that overlies partof the upper endofsaid guide bear- 1 ing and thus limits appreciable longitudinal movement of said guide bearing while permitting limited tilting of said guide bearing relative to said cylinder, a pressure-distributing ring -between the bottom :of said retainer :and the upper end of said guide bearing, a .piston slidably disposed within saidxguide bearing and said cylinder for reciprocating movement, a guide shoe adjacent the bottom of said piston, said guide shoe being dimensioned to move through said elongated tube and to follow said high spots and low spots in guiding said piston, and packing positioned adjacent said retainer, said guide bearing being tiltable to permit said guide shoe to follow said high spots and low spots, the positioning of said packing adjacent said retainer limiting leakage past said packing.

4. A lifting device that comprises a cylinder which has a surface with high-spots and low spots, said cylinder including an elongated tube with a-closed bottom andan open top and ashort tube of larger diameter fixedly secured in telescoping relation to said elongated tube at the upper end of said elongated tube, the top of said elongated tube constituting an inwardly projecting shoulder intermediate the .top and bottom of said cylinder, a guide hearing which is disposed within said cylinder above said shoulder and which has one portion of the exterior thereof fitting loosely within said cylinder and having another portion of the exterior thereof cut away to a diameter less than the diameter of the first said portion of the exterior thereof whereby said guide bearing can tilt Within said cylinder, said guide bearing having the lower end thereof resting upon said shoulder and having the upper end thereof disposed below the upper end of said cylinder, an annular retainer for said guide bearing thatiis disposed within and is securable to said cylinder adjacent the upper end of said guide bearing andthat-overlies part of the upper end of said guide bearing and thus limits appreciable longitudinal movement of said guide bearing while permitting limited tilting of said guide bearing relative to said short tube, a flat annular pressure-distributing ring disposed within said cylinder in engagement with the upper end of said guide bearing and with the bottom of said retainer, a piston slidably disposed within said guide bearing and said cylinder for reciprocating movement, a guide shoe adjacent the bottom of said piston, said guide :shoe being dimensioned to move through said elongated tube, and packing positioned adj acent'said retainer, said guide hearing being tiltable to permit said guide shoe to follow said "high spots and low spots, the positioning of said packing adjacent said retainer limiting leakage past said packing.

HARVARD KAUFMANN HECKER.

References Cited in the file of this patent I UNITED STATES PATENTS Number Name Date 1,637,247 Snyder July 26, 1927 2,001,383 Freed May 14, .1935 2,052,524 Baker Aug. 25, 1936 2,103,465 Kinzie Dec. 28, 1937 2,364,865 Mattingly Dec. 12, 1944 2,373,505 Schnell Apr. 10, 1945 2,439,349 Tack Apr. 6, 1948 2,561,492 Bronk July 24, 1951 

